<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // var arr = [1,2,3]//字面量写法
        // var arr1 = new Array(1,2,3)

        var reg1 = /abc/gi    //g全局  i忽略大小写
        var reg2 = new RegExp('a'+'b'+'c','gi')
    </script>
</body>
</html>